Method for attaching solderballs by selectively oxidizing traces
US6431432B1 · kind B1 · utility
17Cited by
13References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 15, 2000 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Jun 15, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/0315
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A solder mask is placed on a substrate but this solder mask is used to control solder spread but merely helps to protect traces that are distant from the bond pads. The solder mask has an opening that is preferably greater than the area of a die to be attached; this opening exposes both the bond pads and at least portions of traces proximate to the bond pads. The portions of the traces that are proximate to the bond pads are oxidized, thereby preventing solder from flowing onto these portions of the traces during the solder reflow process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.